| Cyclic nucleotides are important physiological active substances in organisms,which are called the second messenger in cells.The content of cyclic c AMP(adenosine monophosphate)in jujube fruit is the highest in all known higher plants.In order to explore the changes of cyclic nucleotides accumulation in ‘huping’ jujube fruits after different anti-cracking agent treatment and provide the theory basis for the enrichment technology establishment of the functional active substances in jujube resources,this experiment used ‘huping’ jujube as the materials,based on the optimized HPLC(high performance liquid chromatography)for the determination of the content of c AMP and c GMP(cyclic guanosine monophosphate)in ‘huping’ jujube fruits and the activity of cyclic nucleotides-metaboling enzymes,the main results are as follows:1.The response surface method was used to optimize the process for the ultrasonic-assisted extraction of cyclic nucleotide from ‘huping’ jujube fruits.The optimal process model was obtained as follows: the ultrasonic power 140 W,the ultrasonic time 20.072 min,soivent ratio 1:6.947,and ethanol concentration 20.163%.Under the optimum extraction conditions,the theoretical maximum value of c AMP extraction was 165.23 μg·g-1 FW,actual value was 155.47 μg·g-1 FW,and c GMP was 133.85 μg·g-1 FW,actual value was 130.13 μg·g-1 FW.2.The results of determination of cyclic nucleotide content in jujube fruits showed: The content of c AMP in ‘huping’ jujube fruits was low from young fruits period to white-mature period,rapidly accumulated from white-mature period to complete-mature period,and the content of c GMP in ‘huping’ jujube fruits slightly decreased from young fruit period to white-mature period,and gently increased from white-mature period to complete-mature period.For CK,the highest content of c AMP and c GMP in ‘huping’ jujube fruits were on 11 th September in crisp-mature period,and for group Zaofengbao、Kelieyihao and Gibberellin treatment,the highest content of c AMP and c GMP were on 22 th September in complete-mature period.Statistical analysis results showed: Spraying anti-cracking agents Kelieyihao reduced the content of c AMP in jujube fruits on 21 th August in white-mature period,but had no significant effect for c GMP,and there were no significant effect on the content of c AMP and c GMP for spraying Zaofengbao and Gibberellin.On 21 th August in white-mature period,the contents of c AMP and c GMP in ‘huping’ jujube fruits were significantly reduced by spraying Zaofengbao and Kelieyihao,but no significant effect was founded by spraying Gibberellin.On 11 th September in crisp-mature period,the contents of c AMP and c GMP in ‘huping’ jujube fruits were significantly reduced by spraying Zaofengbao and Kelieyihao,Gibberellin treatment reduced the content of c AMP,but had no significant effect on the content of c GMP.There were no significant effect on the content of c AMP and c GMP for spraying these three anti-cracking agents.3.The results of determination of cyclic nucleotide metabolic enzyme activity indicated: From 21 th July to 1th August in young fruits period,the activity of AC(adenylate cyclase)in ‘huping’ jujube fruits was reduced by 27.02%,the activity of PDE(phosphodiesterase)was high.With the development and maturity of the fruits,the activity of AC gradually increased,while PDE showed a trend of decline,and the content of c AMP accumulated as the fruits matured.The activity of GC(guanylate cyclase)in ‘huping’ jujube showed a gentle rising trend during the whole development and maturity stage,while the activity of PDE decreased and c GMP accumulated,but the content was less than c AMP,and the content of c GMP in the mature stage was 36% less than c AMP on average.Statistical analysis results showed: Spraying Zaofengbao and Kelieyihao increased the activity of AC in ‘huping’ jujube fruits significantly on 11 th August in white-mature period,and reduced it significantly on September 11 in crisp-mature period.Spraying Gibberellin could significantly improve the activity of AC and GC in the jujube fruits on 11 th August in white-mature period,and improve the activity of AC in the jujube fruits on 21 th August in white-mature period,and reduced the acticity of AC significantly on 22 th September in complete-mature period.These three anti-cracking agents had no significant effect on PDE in ‘huping’ jujube fruits. |
